1. Field of the Invention
This invention relates generally to image pick up apparatus for a video camera, a facsimile, a scanner, or a copy machine, and particularly to an image pick up apparatus having a pixel compensation circuit for reducing modulation components caused by a color filter during saturation in an image pick up device thereof.
2. Prior Art
A conventional image pick up apparatus generally comprises an image pick up device having a color filter, an amplifier for amplifying an output signal from the image pick up device, a vertical contour compensation circuit having a horizontal low-pass circuit and a horizontal contour compensation circuit for obtaining a luminance signal, a color operation circuit for obtaining color difference signals, and an encoder responsive to the luminance signal and the color difference signal for producing a color video signal. Since the luminance signal is modulated by the color filter, it is required that modulation components in the luminance signal have to be taken away. However, in the conventional method using only the horizontal low-pass circuit for cutting such modulation components, when an inputted image signal level changes, such modulation components are not satisfactorily cut away thereby causing disadvantage that zigzag portions in an image are generated at horizontal edge portions in low-frequency components and that jitters are generated in high-frequency components. As a result, an image quality is deteriorated.